Natural gas conveying pipeline based on leakage detection and safety control method thereof

Abstract

The invention provides a natural gas conveying pipeline based on leakage detection and a safety control method thereof, and belongs to the technical field of natural gas conveying, the natural gas conveying pipeline comprises a double-layer pipeline structure formed by an inner-layer pipeline and an outer-layer pipeline, and the outer-layer pipeline and the inner-layer pipeline are each formed by splicing and connecting multiple sections of pipe bodies into a whole; the outer-layer pipeline is coaxially arranged outside the inner-layer pipeline in a sleeving mode, an annular pipeline interlayer is formed between the outer-layer pipeline and the inner-layer pipeline, inert gas is filled in the annular pipeline interlayer, supporting columns are evenly distributed in the annular pipeline interlayer, explosion venting doors are evenly distributed on the surface of the outer-layer pipeline, and the explosion venting doors are communicated with the supporting columns. Each explosion venting door is connected with a leakage detection system, and the leakage detection systems are evenly distributed in the annular pipeline interlayer. The problems that an existing natural gas conveying pipeline is insufficient in safety, lacks real-time pressure monitoring and automatic control and the like are solved, and the safety and reliability of natural gas conveying are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas transportation, and particularly to a natural gas transportation pipeline based on leakage detection and its safety control method. Background Art

[0002] Existing natural gas transportation pipelines have certain defects in terms of safety. When traditional single-layer pipelines transport natural gas, the air in the pipeline is easily mixed with natural gas, which may trigger an explosion risk. Moreover, after the explosion, the natural gas directly enters the air, easily leading to secondary explosions, causing serious casualties and property losses. Although some double-layer pipelines improve safety to a certain extent, they still lack real-time monitoring and automatic control of pipeline pressure and cannot respond to pressure relief and explosion venting situations in a timely and accurate manner. Summary of the Invention

[0003] The purpose of the present invention is to provide a natural gas transportation pipeline based on leakage detection and its safety control method, which solves the problems of insufficient safety, lack of real-time pressure monitoring and automatic control in existing natural gas transportation pipelines, and improves the safety and reliability of natural gas transportation.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A natural gas transportation pipeline based on leakage detection includes a double-layer pipeline structure formed by an inner layer pipeline and an outer layer pipeline. Both the outer layer pipeline and the inner layer pipeline are formed by splicing multiple pipe bodies into one body. It is characterized in that: the outer layer pipeline is coaxially sleeved outside the inner layer pipeline, an annular pipeline interlayer is formed between the outer layer pipeline and the inner layer pipeline, the annular pipeline interlayer is filled with inert gas, support columns are evenly arranged inside the annular pipeline interlayer, explosion vent doors are evenly arranged on the surface of the outer layer pipeline, each explosion vent door is connected to a leakage detection system, and the leakage detection systems are evenly arranged in the annular pipeline interlayer.

[0006] The leakage detection system includes an automatic control module and a pressure sensor. One end of each automatic control module is connected to the corresponding explosion vent door, and the other end of each automatic control module is connected to the pressure sensor. The automatic control module is used to receive pressure signals and control the opening of the explosion vent door, and the pressure sensor is used to monitor the pressure change in the annular pipeline interlayer in real time.

[0007] Furthermore, the pressure of the inert gas filled inside the annular pipeline interlayer is maintained at 0.1 - 0.3 MPa by the pressure sensor, and the explosion vent pressure of the explosion vent door is set at 0.5 - 1.2 MPa.

[0008] Further, the explosion relief doors are provided on each pipe section of the outer layer pipeline, or arranged every 1 - 4 pipelines. The layout density of the explosion relief doors and the leakage detection system is one group per 10 - 50 meters interval. The measuring range of the pressure sensor is 0 - 5 MPa, and the accuracy class is ±0.1% FS.

[0009] Further, the opening conditions of the explosion relief doors include any of the following situations:

[0010] The local pressure of the inner layer pipeline exceeds the preset safety threshold (1.8 - 2.5 MPa);

[0011] The methane concentration in the annular pipeline interlayer exceeds the preset critical value (≥5% volume concentration).

[0012] Further, the inert gas is nitrogen or argon, and its purity ≥99.99%.

[0013] Further, a buffer pad is provided on the support column, and the buffer pad is made of rubber material.

[0014] Further, the explosion relief door adopts a spring - piston structure, and can accurately select the elastic coefficient of the spring according to different explosion relief pressure requirements.

[0015] Further, the automatic control module is built - in with an adaptive algorithm for dynamically detecting the pressure threshold and controlling the opening of the explosion relief door. The adaptive algorithm can optimize the control parameters of the explosion relief door in real - time according to the historical data of pipeline operation, ambient temperature and the change of conveying pressure.

[0016] A safety control method for a natural gas transmission pipeline based on leakage detection, characterized by including the following steps:

[0017] S1: Evacuate the inner layer pipeline to a vacuum degree of ≤10 Pa, fill natural gas into the inner layer pipeline to the working pressure (1.0 - 1.5 MPa), continuously introduce nitrogen into the annular pipeline interlayer, and maintain the pressure in the annular pipeline interlayer at 0.2 MPa ± 0.05 MPa;

[0018] S2: Collect the local pressure data of the inner layer pipeline by the pressure sensor with a period of 0.1 second;

[0019] S3: If it is detected that the natural gas in the inner layer pipeline leaks into the annular pipeline interlayer and the local pressure in the annular pipeline interlayer exceeds 2.0 MPa, or the methane concentration in the annular pipeline interlayer ≥5%, the automatic control module immediately triggers to open the explosion relief door of the outer layer pipeline to discharge the mixed gas.

[0020] Advantages of the present invention:

[0021] Through the design of inert gas isolation and explosion venting, the present invention effectively avoids secondary explosion of natural gas and greatly improves the safety of natural gas transportation. The pressure sensor and the automatic control module achieve real-time monitoring and automatic control of the pressure in the annular pipeline interlayer. Compared with traditional double-layer pipelines, through highly sensitive sensors and the automatic control module, real-time monitoring of leakage and precise pressure relief can be achieved, enabling a safer and more precise response to explosion venting situations and reducing the occurrence of safety accidents. The support columns around the pipeline enhance the structural strength and stability of the pipeline, and the design of rubber buffer pads further improves the anti-external force and anti-pressure fluctuation capabilities of the pipeline. The spring-piston type explosion venting door has a simple structure and high reliability. By reasonably selecting the spring elastic coefficient, the accurate operation of the explosion venting door is ensured, guaranteeing the safe operation of the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the natural gas transportation pipeline based on leakage detection in the present invention;

[0023] Figure 2 It is a schematic external structure diagram of the outer pipeline in the present invention;

[0024] In the figure: 1, annular pipeline interlayer; 2, outer pipeline; 3, inner pipeline; 4, support column; 5, explosion venting door; 6, automatic control module; 7, pressure sensor. SPECIFIC EMBODIMENTS

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention. Therefore, the detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention.

[0026] Such as Figure 1 and Figure 2As shown in the figure, a natural gas transmission pipeline based on leak detection includes a double-layer pipeline structure formed by an inner pipeline 3 and an outer pipeline 2. Both the outer pipeline 2 and the inner pipeline 3 are formed by splicing multiple pipe bodies into one. The outer pipeline 2 is coaxially sleeved outside the inner pipeline 3. The inner pipeline 3 is used to transport natural gas and is made of high-pressure and corrosion-resistant metal materials. An annular pipeline interlayer 1 is formed between the outer pipeline 2 and the inner pipeline 3. The annular pipeline interlayer 1 is filled with inert gas. Support columns 4 are evenly arranged inside the annular pipeline interlayer 1. The support columns 4 are used to enhance the support force between the outer pipeline 2 and the inner pipeline 3, and can also play a buffering role when the outer pipeline 2 and the inner pipeline 3 are subjected to external forces or pressure fluctuations, ensuring the structural strength and stability of the outer pipeline 2 and the inner pipeline 3. Explosion relief doors 5 are evenly arranged on the surface of the outer pipeline 2. Each explosion relief door 5 is connected to a leak detection system. The leak detection system is evenly arranged in the annular pipeline interlayer 1. The leak detection system is used to receive sensor data and control the pressure relief action.

[0027] The leak detection system includes an automatic control module 6 and a pressure sensor 7. One end of each automatic control module 6 is connected to the corresponding explosion relief door 5, and the other end of each automatic control module 6 is connected to the pressure sensor 7. The automatic control module 6 is used to receive pressure signals and control the opening of the explosion relief door 5. The pressure sensor 7 is used to monitor the pressure change in the annular pipeline interlayer 1 in real time.

[0028] As a preferred embodiment of the present invention, the pressure of the inert gas filled inside the annular pipeline interlayer 1 is maintained at 0.1 - 0.3 MPa through the pressure sensor 7, and the explosion relief pressure of the explosion relief door 5 is set at 0.5 - 1.2 MPa.

[0029] The present invention adds a pressure sensor and an automatic control module. By real-time monitoring of the gas pressure in the pipeline interlayer and automatically and precisely controlling the opening of the explosion relief door on the outer pipeline according to the preset pressure threshold, various engineering losses caused by natural gas pipeline leakage can be prevented.

[0030] As a preferred embodiment of the present invention, the explosion relief door 5 is arranged on each pipe body of the outer pipeline, or is arranged every 1 - 4 pipelines. The layout density of the explosion relief door 5 and the leak detection system is one group per 10 - 50 meters interval. The measuring range of the pressure sensor 7 is 0 - 5 MPa, and the accuracy grade is ±0.1% FS.

[0031] As a preferred embodiment of the present invention, the opening conditions of the explosion relief door 5 include any of the following situations:

[0032] The local pressure of the inner pipeline 3 exceeds the preset safety threshold (1.8 - 2.5 MPa);

[0033] The methane concentration in the annular pipe interlayer 1 exceeds the preset critical value (≥5% volume concentration).

[0034] As a preferred embodiment of the present invention, the inert gas is nitrogen or argon, and its purity ≥99.99%.

[0035] As a preferred embodiment of the present invention, a buffer pad is provided on the support column 4. The buffer pad is made of rubber. Using a support column with a rubber buffer pad can not only enhance the support force between the inner and outer layer pipes, but also play a buffering role when the pipe is subjected to external forces or pressure fluctuations, protecting the pipe.

[0036] As a preferred embodiment of the present invention, the explosion relief door 5 adopts a spring - piston structure, and can accurately select the elastic coefficient of the spring according to different explosion relief pressure requirements, ensuring that the explosion relief door 5 can be controlled to open and close by the automatic control module 6 under the set pressure.

[0037] As a preferred embodiment of the present invention, the automatic control module 6 is built - in with an adaptive algorithm for dynamically detecting the pressure threshold and controlling the opening of the explosion relief door. The adaptive algorithm optimizes the control parameters of the explosion relief door 5 in real - time according to the pipeline operation historical data, ambient temperature, and changes in the conveying pressure. The adaptive algorithm is based on existing parameter adaptive control technologies such as model reference adaptive control (MRAC) and self - tuning control. By estimating system parameters (such as pressure, flow rate, etc.) in real - time and adjusting the controller parameters, it provides a highly reliable solution for complex industrial systems.

[0038] The working process of this device is as follows:

[0039] First, evacuate the inner layer pipe 3 to remove the internal air and prevent the natural gas from mixing with air and exploding. Convey natural gas to the evacuated inner layer pipe 3 and introduce an inert gas into the annular pipe interlayer 1. During the conveying process, the pressure sensor 7 and the automatic control module 6 monitor the gas pressure in the annular pipe interlayer 1 in real - time. When the gas in the inner layer pipe 3 leaks into the annular pipe interlayer 1 due to excessive pressure or other engineering practical reasons, the pressure sensor 7 in the annular pipe interlayer 1 transmits the pressure data to the automatic control module 6 and controls the opening of the explosion relief door 5 of the outer layer pipe 2 to complete pressure relief, preventing the excessive pressure in the annular pipe interlayer 1 from damaging the inner layer pipe 3.

[0040] A safety control method for a natural gas transmission pipeline based on leakage detection, comprising the following steps:

[0041] S1: Evacuate the inner pipeline 3 to a vacuum degree of ≤10 Pa, fill the inner pipeline 3 with natural gas to the working pressure (1.0 - 1.5 MPa), continuously introduce nitrogen into the annular pipeline interlayer 1, and maintain the pressure in the annular pipeline interlayer 1 at 0.2 MPa ± 0.05 MPa;

[0042] S2: Collect the local pressure data of the inner pipeline 3 by the pressure sensor 7 at a period of 0.1 second;

[0043] S3: If it is detected that the natural gas in the inner pipeline 3 leaks into the annular pipeline interlayer 1 and the local pressure in the annular pipeline interlayer 1 exceeds 2.0 MPa, or the methane concentration in the annular pipeline interlayer 1 ≥ 5%, the automatic control module 6 immediately triggers to open the explosion vent door 5 of the outer pipeline 2 to discharge the mixed gas.

[0044] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Those skilled in the art can still adjust the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Therefore, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention also intends to include these changes and variations.

Claims

1. A natural gas transmission pipeline based on leakage detection, comprising a double-layer pipeline structure formed by an inner pipeline (3) and an outer pipeline (2), wherein both the outer pipeline (2) and the inner pipeline (3) are formed by splicing multiple pipe bodies into one body, and is characterized in that: The outer pipeline (2) is coaxially sleeved outside the inner pipeline (3). An annular pipeline sandwich layer (1) is formed between the outer pipeline (2) and the inner pipeline (3). The annular pipeline sandwich layer (1) is filled with inert gas. Support columns (4) are evenly arranged inside the annular pipeline sandwich layer (1). Explosion relief doors (5) are evenly arranged on the surface of the outer pipeline (2). Each explosion relief door (5) is connected to a leakage detection system, and the leakage detection systems are evenly arranged in the annular pipeline sandwich layer (1); The leakage detection system includes an automatic control module (6) and a pressure sensor (7). One end of each automatic control module (6) is connected to the corresponding explosion relief door (5), and the other end of each automatic control module (6) is connected to the pressure sensor (7). The automatic control module (6) is used to receive pressure signals and control the opening of the explosion relief door (5). The pressure sensor (7) is used to monitor the pressure change in the annular pipeline sandwich layer (1) in real time.

2. A natural gas transmission pipeline based on leakage detection according to claim 1, characterized in that: The pressure of the inert gas filled inside the annular pipeline sandwich layer (1) is maintained at 0.1 - 0.3 MPa by the pressure sensor (7), and the explosion relief pressure of the explosion relief door (5) is set at 0.5 - 1.2 MPa.

3. A natural gas transmission pipeline based on leakage detection according to claim 2, characterized in that: The explosion relief door (5) is arranged on each pipe section of the outer pipeline, or arranged every 1 - 4 pipelines. The layout density of the explosion relief door (5) and the leakage detection system is one group every 10 - 50 meters. The measuring range of the pressure sensor (7) is 0 - 5 MPa, and the accuracy grade is ±0.1% FS.

4. A natural gas transmission pipeline based on leakage detection according to claim 3, characterized in that: The opening conditions of the explosion relief door (5) include any of the following situations: The local pressure of the inner pipeline (3) exceeds the preset safety threshold (1.8 - 2.5 MPa); The methane concentration in the annular pipeline sandwich layer (1) exceeds the preset critical value (≥5% volume concentration).

5. A natural gas transmission pipeline based on leakage detection according to claim 4, characterized in that: The inert gas is nitrogen or argon, and its purity ≥99.99%.

6. A natural gas transmission pipeline based on leakage detection according to claim 5, characterized in that: A buffer pad is arranged on the support column (4), and the buffer pad is made of rubber material.

7. A natural gas transmission pipeline based on leakage detection according to claim 6, characterized in that: The explosion relief door (5) adopts a spring - piston structure and can accurately select the elastic coefficient of the spring according to different explosion relief pressure requirements.

8. A natural gas transmission pipeline based on leakage detection according to claim 7, characterized in that: The automatic control module (6) is built with an adaptive algorithm for dynamically detecting the pressure threshold and controlling the opening of the explosion relief door. The adaptive algorithm optimizes the control parameters of the explosion relief door (5) in real time according to the historical pipeline operation data, ambient temperature, and changes in the conveying pressure.

9. A safety control method for a natural gas transmission pipeline based on leakage detection, characterized in that, It includes the following steps: S1: Evacuate the inner pipeline (3) to a vacuum degree of ≤10 Pa, fill the inner pipeline (3) with natural gas to the working pressure (1.0 - 1.5 MPa), continuously introduce nitrogen into the annular pipeline interlayer (1), and maintain the pressure in the annular pipeline interlayer (1) at 0.2 MPa ± 0.05 MPa; S2: Collect the local pressure data of the inner pipeline (3) through the pressure sensor (7) at a period of 0.1 second; S3: If it is detected that the natural gas in the inner pipeline (3) leaks into the annular pipeline interlayer (1) and the local pressure in the annular pipeline interlayer (1) exceeds 2.0 MPa, or the methane concentration in the annular pipeline interlayer (1) ≥ 5%, the automatic control module (6) immediately triggers the opening of the explosion relief door (5) of the outer pipeline (2) to discharge the mixed gas.

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